Talking of my interpretation of these pictographs and petroglyphs, I thought I was the geek but the rumors where I'm from says that the americans had multiple language families in 1492 something Indo-European speaker never had. This collection you documented just reconfirms it for me.
That looks some kind of wagon to me. Or maybe a trailer. Probably used to haul the stuff came from the mining site.
That trail reminds me of our first trail trip with our '88 Wrangler YJ. Hoping to finish its restoration and install the Smittybilt SRC roof rack thing coming month.